4 #include <linux/eventfd.h>
5 #include <linux/vhost.h>
7 #include <linux/mutex.h>
8 #include <linux/poll.h>
9 #include <linux/file.h>
10 #include <linux/skbuff.h>
11 #include <linux/uio.h>
12 #include <linux/virtio_config.h>
13 #include <linux/virtio_ring.h>
14 #include <asm/atomic.h>
19 /* Enough place for all fragments, head, and virtio net header. */
20 VHOST_NET_MAX_SG = MAX_SKB_FRAGS + 2,
24 typedef void (*vhost_work_fn_t)(struct vhost_work *work);
27 struct list_head node;
29 wait_queue_head_t done;
35 /* Poll a file (eventfd or socket) */
36 /* Note: there's nothing vhost specific about this structure. */
39 wait_queue_head_t *wqh;
41 struct vhost_work work;
43 struct vhost_dev *dev;
46 void vhost_poll_init(struct vhost_poll *poll, vhost_work_fn_t fn,
47 unsigned long mask, struct vhost_dev *dev);
48 void vhost_poll_start(struct vhost_poll *poll, struct file *file);
49 void vhost_poll_stop(struct vhost_poll *poll);
50 void vhost_poll_flush(struct vhost_poll *poll);
51 void vhost_poll_queue(struct vhost_poll *poll);
58 /* The virtqueue structure describes a queue attached to a device. */
59 struct vhost_virtqueue {
60 struct vhost_dev *dev;
62 /* The actual ring of buffers. */
65 struct vring_desc __user *desc;
66 struct vring_avail __user *avail;
67 struct vring_used __user *used;
71 struct eventfd_ctx *call_ctx;
72 struct eventfd_ctx *error_ctx;
73 struct eventfd_ctx *log_ctx;
75 struct vhost_poll poll;
77 /* The routine to call when the Guest pings us, or timeout. */
78 vhost_work_fn_t handle_kick;
80 /* Last available index we saw. */
83 /* Caches available index value from user. */
86 /* Last index we used. */
92 /* Log writes to used structure. */
96 struct iovec indirect[VHOST_NET_MAX_SG];
97 struct iovec iov[VHOST_NET_MAX_SG];
98 struct iovec hdr[VHOST_NET_MAX_SG];
100 /* We use a kind of RCU to access private pointer.
101 * All readers access it from worker, which makes it possible to
102 * flush the vhost_work instead of synchronize_rcu. Therefore readers do
103 * not need to call rcu_read_lock/rcu_read_unlock: the beginning of
104 * vhost_work execution acts instead of rcu_read_lock() and the end of
105 * vhost_work execution acts instead of rcu_read_lock().
106 * Writers use virtqueue mutex. */
108 /* Log write descriptors */
109 void __user *log_base;
110 struct vhost_log log[VHOST_NET_MAX_SG];
114 /* Readers use RCU to access memory table pointer
115 * log base pointer and features.
116 * Writers use mutex below.*/
117 struct vhost_memory *memory;
118 struct mm_struct *mm;
120 unsigned acked_features;
121 struct vhost_virtqueue *vqs;
123 struct file *log_file;
124 struct eventfd_ctx *log_ctx;
125 spinlock_t work_lock;
126 struct list_head work_list;
127 struct task_struct *worker;
130 long vhost_dev_init(struct vhost_dev *, struct vhost_virtqueue *vqs, int nvqs);
131 long vhost_dev_check_owner(struct vhost_dev *);
132 long vhost_dev_reset_owner(struct vhost_dev *);
133 void vhost_dev_cleanup(struct vhost_dev *);
134 long vhost_dev_ioctl(struct vhost_dev *, unsigned int ioctl, unsigned long arg);
135 int vhost_vq_access_ok(struct vhost_virtqueue *vq);
136 int vhost_log_access_ok(struct vhost_dev *);
138 int vhost_get_vq_desc(struct vhost_dev *, struct vhost_virtqueue *,
139 struct iovec iov[], unsigned int iov_count,
140 unsigned int *out_num, unsigned int *in_num,
141 struct vhost_log *log, unsigned int *log_num);
142 void vhost_discard_vq_desc(struct vhost_virtqueue *);
144 int vhost_add_used(struct vhost_virtqueue *, unsigned int head, int len);
145 void vhost_signal(struct vhost_dev *, struct vhost_virtqueue *);
146 void vhost_add_used_and_signal(struct vhost_dev *, struct vhost_virtqueue *,
147 unsigned int head, int len);
148 void vhost_disable_notify(struct vhost_virtqueue *);
149 bool vhost_enable_notify(struct vhost_virtqueue *);
151 int vhost_log_write(struct vhost_virtqueue *vq, struct vhost_log *log,
152 unsigned int log_num, u64 len);
154 #define vq_err(vq, fmt, ...) do { \
155 pr_debug(pr_fmt(fmt), ##__VA_ARGS__); \
156 if ((vq)->error_ctx) \
157 eventfd_signal((vq)->error_ctx, 1);\
161 VHOST_FEATURES = (1 << VIRTIO_F_NOTIFY_ON_EMPTY) |
162 (1 << VIRTIO_RING_F_INDIRECT_DESC) |
163 (1 << VHOST_F_LOG_ALL) |
164 (1 << VHOST_NET_F_VIRTIO_NET_HDR),
167 static inline int vhost_has_feature(struct vhost_dev *dev, int bit)
169 unsigned acked_features = rcu_dereference(dev->acked_features);
170 return acked_features & (1 << bit);